An example of the conventional apparatus for recycling scrapped POLYLON is disclosed in Taiwanese Patent Pub. No. 197976 titled "An apparatus for recycling scrapped POLYLON and the operation method thereof". The apparatus disclosed by the above-mentioned Taiwanese Patent is characterized in a furnace having a door with a cover which, when being closed to the door, allows the furnace to define a completely sealed space, a heating pipe system disposed inside the furnace on a bottom thereof, heat medium disposed between the heating pipe system and an inner wall of the furnace for evenly distributing the heat generated from the heating pipe system to the inner wall of the furnace, a collecting container disposed below the furnace to collect the molten POLYLON scraps, a control panel for maintaining the in-furnace temperature at a fixed level, and a chimney with filter screen for exhausting gas produced during the recycling process with minimized air pollution.
The apparatus disclosed in Taiwanese Patent Pub. No. 197976 has the following disadvantages when it is empolyed to recycle the scrapped POLYLON:
1. The pieces of scrapped POLYLON are different in their shape and size and they are usually dumped into the furnace without being sorted based on their shape or size. This causes many gaps existed between the scrap pieces in the furnace and prevents the pieces from closely contacting with one another when being heated. Although the heating pipe system is disposed on a bottom of the furnace and the heat produced by the heating pipe system can be evenly distributed via the heat medium to the inner wall of the furnace, the unsorted and disarrayed POLYLON scraps with only small contact area between one another often prevent the heat from evenly conducting and the scraps from absorbing sufficient heat to melt completely. Therefore, prolonged time of heating is required to thoroughly melt the scrapped POLYLON pieces. This is, of course, an unnecessary waste of heat. In addition, the reduced thermal efficiency increases the produced waste gas. All of these do not meet the requirements of economical benefits and actual needs. PA1 2. To enable complete melting of scrapped POLYLON pieces and reduced heating time, the scraps must be sorted before they are dumped into the furnace for melting. However, it is another labor and time consuming work to sort the scraps and will do little help to the previously disclosed apparatus when viewing from the economical point. PA1 3. It is a must to keep the entire recycling process (from the melting of scraps to the filtering and exhausting of wasted gas) in continuous steps and in a completely sealed space, so as to ensure the harmlessness of the exhausted gas. However, in the apparatus disclosed in Taiwanese Patent Pub. No. 197976, the cover of the door of the furnace must be opened to dump the subsequent scraps into the furnace for melting. And, the waste gas inside the furnace will quickly escape from the furnace as soon as the door thereof is opened. This forms a drawback in the required continuous and sealed recycling process. In addition, such waste gas is usually hazardous to the health of operators and the public sanitation due to the air pollution it causes.
It is therefore desirable to develop an improved apparatus for recycling scrapped polylon on which not only melts the scrapped POLYLON but also effectively achieves the waste gas pollution control to eliminate the disadvantages existed in the conventional apparatus.